The Investigation of Geometric Parameters on the Injection Characteristic of the High Pressure Common-Rail Injector

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Ling Wang ◽  
Guo-Xiu Li ◽  
Chun-Long Xu ◽  
Xing Xi ◽  
Xiao-Jun Wu ◽  
...  
Keyword(s):  
Injection Rate ◽  
Common Rail ◽  
Needle Valve ◽  
Fuel Injector ◽  
Pressure Injection ◽  
Common Rail Pressure ◽  
Outlet Hole ◽  
Common Rail Injector ◽  
The Common ◽  
Injection Pulse

According the actual structure and working principle of a fuel injector to build a model of the common-rail injector, including the control valve, the solenoid valve, and the needle valve of the injector. The model includes the leakage model for the control piston and needle valve that takes into account increasing leakage at high pressure. The performance of the fuel injector is investigated using a one-dimensional numerical model. Analyzing the effect of the system and structure parameters including common-rail pressure, injection pulse width, inlet and outlet hole diameter, and the injection nozzle on the injection characteristics of the fuel injector. Results show that the geometric parameter is the main property affecting the flow characteristic of the injector, which includes the flow rate of inlet and outlet hole, pressure waves in the control chamber and injection rate. The common-rail pressure, injection pulse width and the geometric parameters mainly affect the injection performance, such as the injection rate and injected volume. The investigation result can provide some useful information to improve the injection characteristic in follow-up studies.

scholarly journals Providing Boot-Type Injection Rate Shape by Electric Impulse Control of the Common Rail Injector

2020 ◽  
pp. 32-42
Author(s):  
A.Y. Dunin ◽  
M.G. Shatrov ◽  
L.N. Golubkov ◽  
A.L. Yakovenko
Keyword(s):  
Diesel Engines ◽  
Fuel Injection ◽  
Control Valve ◽  
Road Construction ◽  
Injection Rate ◽  
Common Rail ◽  
Oxide Content ◽  
Common Rail Injector ◽  
Electric Impulse ◽  
The Common

For effective reduction of noise level and nitrogen oxide content in exhaust fumes of diesel engines, multistage fuel injection is used in combination with control of the front edge shape of the main injection. At the Moscow Automobile and Road Construction State Technical University (MADI), a method of control of the injection rate shape using an electric impulse was proposed, which was applied to the electromagnet of the control valve of the injector of the common rail fuel system. A computational and experimental analysis of the possibility of boot-type injection rate shape was carried out. The studies involved three most used designs of the common rail injector (CRI): CRI 1 featuring a control valve with shut-off cone and piston; CRI 2 consisting of a flat-lock control valve and a needle, which does not overlap the drain when the needle is in the highest position; CRI 3 with an injector that partially overlaps the drain. It was established that friction in the control valve piston and the guide surface pair of CRI 1 complicated the implementation of the boot-type injection rate due to its smoothing. CRI 2 and CRI 3 provide boot-type injection rate at different pressures in the fuel accumulator. The CRI 3 example shows that the instability of fuel supply during boot-type injection rate is comparable with that of fuel pre-injection, which is widely used in the organization of the common rail diesel engines working process.

scholarly journals INFLUENCE OF PRESSURE OSCILLATIONS IN COMMON RAIL INJECTOR ON FUEL INJECTION RATE

2020 ◽  
pp. 579
Author(s):  
Mikhail G. Shatrov ◽  
Andrey U. Dunin ◽  
Pavel V. Dushkin ◽  
Andrey L. Yakovenko ◽  
Leonid N. Golubkov ◽  
...  
Keyword(s):  
Diesel Fuel ◽  
Fuel Injection ◽  
Injection Rate ◽  
Common Rail ◽  
Needle Valve ◽  
Rail Pressure ◽  
Pressure Oscillations ◽  
Multiple Injections ◽  
Double Injection ◽  
Common Rail Injector

Fuel injection causes considerable oscillations of fuel pressure at the injector inlet. One of the reasons is hydraulic impact when the needle valve closes. For multiple injections, the previous injections affect the following. As both the fuel pressure in rail pac and the injection rate grow, the oscillations increase. The pressure oscillation range at the common rail injector inlet at pac=1500 bar is up to 350 bar, and at the rail pressure pac=500 bar, the amplitude decreases to 80 bar. Physical properties of the fuel are also important. As the viscosity of the fuel increases, its hydraulic friction grows which results in a rapid damping of pressure oscillations. The data for an injector operating on sunflower oil is presented. As compared with diesel fuel, the oscillations range decreases from 400 to 250 bar at the same operating mode. The influence of the interval between the impulses of a double injection on the injection rate of the second fuel portion was investigated. Superposition of two waves during multiple injections may result in amplification and damping of the oscillations. Simulation was performed to estimate the influence of fuel type and time interval Δτ between control impulses of a double injection on the injection quantity of the second portion at pressures of 2000-3000 bar. When the rail pressure pac grows, the oscillations and their impact on the injection process increase. For diesel fuel at pressure of pac=2000 bar, the variation in injection rates of the second portion is 2.36-4.62 mg, and at pac=3000 bar – 1.58-6.63 mg.

Understanding the Acoustic Oscillations Observed in the Injection Rate of a Common-Rail DI Diesel Injector

2012 ◽  
Author(s):  
Julien Manin ◽  
Alan Kastengren ◽  
Raul Payri
Keyword(s):  
Acoustic Analysis ◽  
Injection Rate ◽  
Point Of View ◽  
Common Rail ◽  
Acoustic Oscillations ◽  
Real Rate ◽  
The Real ◽  
Injection Process ◽  
Engine Combustion ◽  
Common Rail Injector

Measuring the rate of injection of a common-rail injector is one of the first steps for diesel engine development. At the same time, this information is of prime interest for engine research and modeling as it drives spray development and mixing. On the other hand, the widely used long-tube method provides results that are neither straightforward, nor fully understood. This study performed on a 0.09 mm axially drilled single-hole nozzle is part of the Engine Combustion Network (ECN) and aims at analyzing these features from an acoustic point of view to separate their impact on the real injection process and on the results recorded by the experimental devices. Several tests have been carried out for this study including rate of injection and momentum, X-ray phase-contrast of the injector and needle motion or injector displacement. The acoustic analysis revealed that these fluctuations found their origin in the sac of the injector and that they were the results of an interaction between the fluid in the chamber (generally gases) and the liquid fuel to be injected. It has been observed that the relatively high oscillations recorded by the long-tube method were mainly caused by a displacement of the injector itself while injecting. In addition, the results showed that these acoustic features also appear on the momentum flux of the spray which means that the real rate of injection should present such behavior.

Optical Sensor for the Needle Lift Detection in the Common Rail Injector

2019 ◽  
Author(s):  
Carlo Coratella ◽  
Lewis Parry ◽  
Amrit Sahu ◽  
Hongming Xu
Keyword(s):  
Optical Sensor ◽  
Common Rail ◽  
Common Rail Injector ◽  
The Common

DIAGNOSIS OF INJECTORS THROUGH COMMON RAIL PRESSURE MEASUREMENT

2011 ◽  
Vol 159 (1) ◽  
pp. 110-122
Author(s):  
Mirosław KARCZEWSKI ◽  
Krzysztof KOLIŃSKI
Keyword(s):  
Pressure Sensor ◽  
Pressure Measurement ◽  
Common Rail ◽  
Diagnostic Methods ◽  
Fuel System ◽  
Rail Pressure ◽  
Dynamic Changes ◽  
Common Rail Pressure ◽  
The Common ◽  
Pressure Changes

More and more compress engines contain common rail fuel systems. This type of fuel systems injectors are supplied with high pressurised petroleum from the common rail. Dynamic changes of pressure in rail are caused by injection events and fuel supply. The pressure sensor mounted by manufactures in the common rail enables observing and measuring changes in pressure. Pressure changes depend on the phenomena occurring during injection and pumping processes. Every change in each process influences pressure changes in the common rail. The aim of the paper is to elaborate on diagnostic methods of the C-R fuel system based on dynamic changes of pressure in the rail.

scholarly journals Study on Influencing Factors and Laws of Fuel Injection Consistency of Common Rail Injector

2021 ◽  
Vol 2097 (1) ◽  
pp. 012001
Author(s):  
Ziwei Zhang ◽  
Chunlong Xu
Keyword(s):  
Fuel Injection ◽  
Solenoid Valve ◽  
Hole Diameter ◽  
Operating Conditions ◽  
Nozzle Diameter ◽  
Common Rail ◽  
Valve Lift ◽  
Needle Valve ◽  
Inlet Hole ◽  
Common Rail Injector

Abstract In order to study the influence of parameters of common rail injector internal components on cycle injection consistency, its simulation model is established by AMESim, and the model is validated by the experimental injection rate data. The effects of solenoid valve spring preload, gag bit lift, fuel discharge hole diameter, fuel inlet hole diameter, needle valve lift, needle valve preload and nozzle diameter on the change of injection quantity under different operating conditions are studied by simulation method, and the impact weight of each parameter on fuel injection consistency is analyzed. The results show that the preload of solenoid valve, fuel discharge hole diameter, oil inlet hole diameter, needle valve lift and nozzle diameter are the main parameters affecting the consistency of cycle injection. The percentages of five parameters influencing on the consistency of cyclic injection are 8.68-16.84%, 11.41-23.68%, 17.2086-37.74%, 12.772-18.34% and 9.69-37.27% respectively.

scholarly journals A control method of fuel distribution by combustion chamber zones and its dependence on injection conditions

2018 ◽  
Vol 22 (Suppl. 5) ◽  
pp. 1425-1434 ◽  
Author(s):  
Mikhail Shatrov ◽  
Valery Malchuk ◽  
Andrey Dunin ◽  
Ivan Shishlov ◽  
Vladimir Sinyavski
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Effective Cross Section ◽  
Injection Rate ◽  
Operating Conditions ◽  
Common Rail ◽  
Fuel System ◽  
Excessive Pressure ◽  
The Common ◽  
The Impact

A method of fuel injection rate shaping of the Diesel engine common rail fuel system with common rail injectors and solenoid control is proposed. The method envisages the impact on control current of impulses applied to the control solenoid valve of the common rail injectors for variation of the injection rate shape. At that, the fuel is supplied via two groups of injection holes. The entering edges of the first group with the coefficient of flow, ??B, were located in the sack volume and the entering edges of the second group (coefficient of flow, ??H) - on the locking taper surface of the nozzle body. The coefficients of flow, ??B, and ??H differ considerably and depend on the valve needle position. This enables to adjust the injection quantity by injection holes taking into account operating conditions of the Diesel engine and hence - by the combustion chamber zones. Using the constant fuel flow set-up, characteristic of the effective cross-section of the common rail fuel system injector holes was investigated. The diameter of injector holes was 0.12 ? 0.135 mm. The excessive pressure at the entering edges varied from 30 to 150 MPa and more and the excessive pressure in the volume behind the output edge - from 0 to 16 MPa.

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